A torque converter is a form of a hydrodynamic fluid coupling and may be used to transfer rotating power from a power source to another driven component. For example, a torque converter may provide a hydrodynamic fluid coupling between an internal combustion engine or electric motor and a transmission. The torque converter may include an impeller driven by the power source (e.g. internal combustion engine), a turbine operatively coupled to the driven component (e.g. transmission) and a stator positioned between the impeller and turbine to redirect fluid flowing from the turbine to the impeller. The torque converter may be capable of multiplying torque under conditions where the input rotational speed is significantly different from the output rotational speed.
An impeller clutch may be provided in the torque converter to allow for selective driving of the impeller by the power source. The impeller clutch may therefore be positioned between the power source and the impeller to operatively couple the two together when engaged, and alternatively uncouple the impeller from the power source when not engaged. In known impeller clutch designs a disc stack including a plurality of alternating friction discs and separator plates may be provided with a piston plate on one side. An actuating device is positioned adjacent the piston plate and opposite the disc stack to compress the disc stack when actuated. The friction discs of the disc stack include a splined inner diameter that engages the impeller or an adapter and the separator plates include a splined outer diameter that engages a rotating housing driven by the power source.
U.S. Pat. No. 7,815,026, issued Oct. 19, 2010, discloses a torque converter having an impeller, a turbine, a stator and an impeller clutch for alternately engaging and disengaging a drive connection between the impeller and a power source. Existing impeller clutch designs suffer from disadvantages and present opportunities for improvement. One disadvantage to known designs is that a splined interface at the outer diameter of the separator plates of the disc stack leaves little open space for cooling fluid and may impede fluid flow through the disc stack, resulting in elevated temperatures and reduced efficiency of the torque converter under some operating conditions.
The torque converter of the present disclosure includes an improved impeller clutch.